1. Field of the Invention
The present invention relates to a method for verifying the coherence of the takeoff parameters of an aircraft from an airport with an available runway length at the moment of takeoff.
It also relates to an aircraft capable of employing the method according to the invention.
2. Discussion of the Background
In general, the present invention relates to the field of takeoff safety of an aircraft, by verifying the coherence of the takeoff parameters of an aircraft with the available runway length at the moment of takeoff.
In practice, during preparation for takeoff of an aircraft, takeoff parameters must be inserted into the avionic systems interfacing with the pilots, in order to be initialized into the takeoff configuration and to remind the pilots of the piloting information items necessary during a phase of ground roll and a phase of initial climb during takeoff of the aircraft.
A calculation making it possible to optimize the performances of the aircraft during takeoff is performed.
This calculation depends in particular on the state of the aircraft (weight, configuration, etc.), on external conditions (temperature, wind, etc.), on the takeoff runway (length, condition, slope, etc.) and on the policy of the company chartering the aircraft (aircraft configuration, engine thrust, etc.)
This calculation may be performed manually by the pilots, or electronically by the pilots using tools available on board the aircraft, or else electronically by operators situated on the ground, communication means then making it possible for the results of the calculation to be provided to the pilots.
The parameters resulting from this calculation must then be inserted by the pilots into the avionic systems, either manually via an FMS interface (acronym for the English term “Flight Management System”) of the MCDU type (acronym for the English term “Multi Purpose Control and Display Unit”) or MFD type (acronym for the English term “Multi Function Display”), or by downloading parameters sent by operators situated on the ground.
By means of these information items which may be displayed, and of directions from air traffic and airport controllers, the pilots taxi the aircraft to the takeoff runway with the intention of taking off therefrom.
This takeoff procedure has risk factors at several levels, especially during operations of calculation of the airplane performances for takeoff, during insertion of the parameters into the avionic systems or else during reception of directions from the air traffic and airport controllers.
In general, the entirety of the takeoff phase, from preparation to accomplishment thereof, is a complex phase of aircraft operation, in which a large number of participants are involved.
Operational procedures as well as automatic verifications exist to identify errors in the takeoff parameters of an aircraft.
In particular, French Patent 2894046 describes a method for detecting an error of input of a takeoff parameter into a flight management system.
In that document, a takeoff distance is calculated on the basis of takeoff parameters entered into the flight management system, then is compared with an available takeoff distance stored in memory in the flight management system and corresponding to a planned takeoff runway.
Nevertheless, this planned takeoff runway corresponds to a takeoff runway introduced into the system during flight preparation for the aircraft, and it may not correspond to the actual takeoff runway, especially in the case of airport navigation errors.
From U.S. Pat. No. 6,614,397 there is also known a method for alerting pilots automatically when takeoff of an aircraft is being attempted from an erroneous takeoff runway, when a detected aircraft position does not correspond to a predetermined position, stored in memory, on the planned takeoff runway.
This alert message prompts the pilots then to interrupt the takeoff phase of the aircraft.
Under the conditions of the prior art, alert messages thus may be sent to the pilots, interrupting the takeoff regardless of what actually are the real possibilities for takeoff of the aircraft as a function of its position in the airport.